c 和 指针 第七章

1.编写函数

       void  written_amount( unsigned int  amount,  char  char  *buffer);

   它把amount表示的值转换为单词形式，并储存于buffer中。这个函数可以在一个打印支票的程序中使用。例如：如果

   amount的值为16312，那么buffer中储存的字符串应该是

      SIXTEEN  THOUSAND  THREE  HUNDRED  TWELVE

   调用程序应该保证buffer缓冲区的空间足够大。

#include<stdio.h>#include<string.h>/*** Conver a numeric value to words.*/static char  *digits[] = {"","ONE ","TWO ","THREE ","FOUR ","FIVE ","SIX ","SEVEN ","EIGHT ","NINE ","TEN ","ELEVEN ","TWELVE ","THIRTEEN ","FOURTEEN ","FIVTEEN ","SIXTEEN ","SEVENTEEN ","EIGHTEEN ","NINTEEN "};static char *tens[] = {"","","TWENTY ","THIRTY ","FORTY ","FIFTY ","SIXTY ","SEVENTY ","EIGHTY ","NINETY "};static char *magnitudes[] = {"", "THOUSAND ", "MILLION ", "BILLION " };static void do_one_groud(unsigned int amount, char *buffer, char **magnitude){int value;value = amount / 1000;if(value > 0)do_one_groud(value,buffer,magnitude+1);amount %= 1000;value = amount / 100;if(value > 0){strcat(buffer,digits[value]);strcat(buffer,"HUNRED ");}value = amount % 100;if(value >= 20){strcat(buffer,tens[value/10]);value %= 10;}if(value > 0)strcat(buffer,digits[value]);if(amount > 0)strcat(buffer,*magnitude);}void written_amount(unsigned int amount, char *buffer){if( amount == 0)strcpy(buffer, "ZERO");else{*buffer = '\0';do_one_groud(amount, buffer, magnitudes);}}int main(void){int amount = 16000321;char buffer[1000];written_amount(amount,buffer);puts(buffer);return 1;}